Remove upgrade notes from CHANGELOG

This content of this section is incomplete (missing 5.0.0) and redundant with the CHANGELOG.

Author: Aaron Lane

README.md

@@ -108,22 +108,6 @@ Then perform the following commands on the root folder:
 - `terraform apply` to apply the infrastructure build
 - `terraform destroy` to destroy the built infrastructure
 
-## Upgrade to v3.0.0
-
-v3.0.0 is a breaking release. Refer to the
-[Upgrading to v3.0 guide][upgrading-to-v3.0] for details.
-
-## Upgrade to v2.0.0
-
-v2.0.0 is a breaking release. Refer to the
-[Upgrading to v2.0 guide][upgrading-to-v2.0] for details.
-
-## Upgrade to v1.0.0
-
-Version 1.0.0 of this module introduces a breaking change: adding the `disable-legacy-endpoints` metadata field to all node pools. This metadata is required by GKE and [determines whether the `/0.1/` and `/v1beta1/` paths are available in the nodes' metadata server](https://cloud.google.com/kubernetes-engine/docs/how-to/protecting-cluster-metadata#disable-legacy-apis). If your applications do not require access to the node's metadata server, you can leave the default value of `true` provided by the module. If your applications require access to the metadata server, be sure to read the linked documentation to see if you need to set the value for this field to `false` to allow your applications access to the above metadata server paths.
-
-In either case, upgrading to module version `v1.0.0` will trigger a recreation of all node pools in the cluster.
-
 <!-- BEGINNING OF PRE-COMMIT-TERRAFORM DOCS HOOK -->
 ## Inputs